Catalase (EC 1.11.1.6) is an enzyme that catalyses the decomposition of hydrogen peroxide into water and molecular oxygen. It can be used to remove residual hydrogen peroxide in applications where hydrogen peroxide is added e.g. for pasteurization or bleaching.
Thus, it has been suggested to use catalase in the textile industry for the removal of hydrogen peroxide from fabric which is bleached by an alkaline hydrogen peroxide treatment before dyeing (GB 2,216,149, JP-A 2-104781) The peroxide bleaching is commonly done at high pH and temperature, e.g. 80.degree.-100.degree. C. and pH 10 or higher, and it is therefore desirable to use a catalase with good stability at high pH and temperature in order to avoid or minimize the need for neutralization and cooling.
Catalases are known both from animal sources (e.g. cow liver) and from many different microorganisms. JP-A 2-76579 discloses catalase from Aspergillus niger strain NFAG-2 at pH 3-8. GB 2,216,149 states that catalase from Penicillium has good stability at high pH.
It is the object of this invention to provide an improved catalase for use in such processes.